Energized LED (light-emitting diode) will present a phenomenon of temperature rise, which is especially serious in case of large LED chip or when LED's are densely arranged. In that event LED lightness is impaired, radiation wavelength of LED be changed, working life of LED is influenced, and even LED will be permanently damaged.
Along with continuous extension of LED application, more and more super-bright full-color large LED display screens and LED illuminating devices, where LED's are densely arranged, are widely applied and have brought forth problem of heat rising. It is important for LED to achieve good heat dissipation. Conventional methods of heat dissipation for LED are embodied in forming technology of LED, e.g. metallic pinouts of LED are made of flat metal strips. Usually the surface area of printed-circuit board (PCB), on which LED's are implanted, is made as large as possible to facilitate heat dissipation. But these measures are limited by such highly dense arrangement of circuits on PCB, so that heat dissipation effects are seriously restricted, and up to now there is no ideal heat dissipation structure for PCB of LED's.